powerpc: Remove all usages of NO_IRQ

NO_IRQ has been == 0 on powerpc for just over ten years (since commit
0ebfff1491ef ("[POWERPC] Add new interrupt mapping core and change
platforms to use it")). It's also 0 on most other arches.

Although it's fairly harmless, every now and then it causes confusion
when a driver is built on powerpc and another arch which doesn't define
NO_IRQ. There's at least 6 definitions of NO_IRQ in drivers/, at least
some of which are to work around that problem.

So we'd like to remove it. This is fairly trivial in the arch code, we
just convert:

    if (irq == NO_IRQ)	to	if (!irq)
    if (irq != NO_IRQ)	to	if (irq)
    irq = NO_IRQ;	to	irq = 0;
    return NO_IRQ;	to	return 0;

And a few other odd cases as well.

At least for now we keep the #define NO_IRQ, because there is driver
code that uses NO_IRQ and the fixes to remove those will go via other
trees.

Note we also change some occurrences in PPC sound drivers, drivers/ps3,
and drivers/macintosh.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

2 files changed, 3 insertions, 3 deletions

diff --git a/arch/powerpc/platforms/83xx/mpc832x_rdb.c b/arch/powerpc/platforms/83xx/mpc832x_rdb.c
index 2ef03e7d248c..0d6a62fc5864 100644
--- a/arch/powerpc/platforms/83xx/mpc832x_rdb.c
+++ b/arch/powerpc/platforms/83xx/mpc832x_rdb.c
@@ -89,7 +89,7 @@ static int __init of_fsl_spi_probe(char *type, char *compatible, u32 sysclk,
 			goto err;
 
 		ret = of_irq_to_resource(np, 0, &res[1]);
-		if (ret == NO_IRQ)
+		if (!ret)
 			goto err;
 
 		pdev = platform_device_alloc("mpc83xx_spi", i);
diff --git a/arch/powerpc/platforms/83xx/suspend.c b/arch/powerpc/platforms/83xx/suspend.c
index fcbea4b51a78..24717d060008 100644
--- a/arch/powerpc/platforms/83xx/suspend.c
+++ b/arch/powerpc/platforms/83xx/suspend.c
@@ -352,7 +352,7 @@ static int pmc_probe(struct platform_device *ofdev)
 		return -ENODEV;
 
 	pmc_irq = irq_of_parse_and_map(np, 0);
-	if (pmc_irq != NO_IRQ) {
+	if (pmc_irq) {
 		ret = request_irq(pmc_irq, pmc_irq_handler, IRQF_SHARED,
 		                  "pmc", ofdev);
 
@@ -400,7 +400,7 @@ out_syscr:
 out_pmc:
 	iounmap(pmc_regs);
 out:
-	if (pmc_irq != NO_IRQ)
+	if (pmc_irq)
 		free_irq(pmc_irq, ofdev);
 
 	return ret;